<!--
     Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/
-->
<html>
<script type="text/javascript">
window.onload = function() {
  var c = document.getElementById("b");
  var ctx = c.getContext("2d");
  ctx.fillStyle = "rgb(0,0,0)";
  ctx.fillRect(0,0,100,100);
}
</script>
<style>
#a {
  width: 200px;
  height: 200px;
  background-color: rgb(0,255,0);
}
#b {
  width: 100px;
  height: 100px;
}
</style>
<div id="a">
  <canvas width="100" height="100" id="b"/>
</div>
</html>
